fr Thu, 23 May 2013 20:55:20 +0200 http://cedric.cnam.fr/index.php/publis/article/view?id=2747 http://cedric.cnam.fr/index.php/publis/article/view?id=2747 , Thu, 23 May 2013 20:55:20 +0200 ILJ Paper http://cedric.cnam.fr/index.php/publis/article/view?id=2746 http://cedric.cnam.fr/index.php/publis/article/view?id=2746 , Thu, 23 May 2013 20:51:58 +0200 ILJ Paper http://cedric.cnam.fr/index.php/publis/article/view?id=2745 http://cedric.cnam.fr/index.php/publis/article/view?id=2745 We investigate in this paper the resource allocation problem in an uplink OFDMA multiuser system. We focus on the Proportional Fairness approach which aims to maximize the system throughput and while ensuring fairness between users. In this paper, we propose a Weighted Proportional Fair algorithm for resource allocation that introduces priorities between users to better exploit good channel conditions in the cell center. We also perform a theoretical analysis to compare both standard and weighted proportional fair algorithms. Simulation results, compared to existing algorithms, show that the proposed algorithm approaches the max sum rate upper bound but still maintains sufficient fairness between users. Tue, 14 May 2013 15:52:58 +0200 LAETITIA Paper http://cedric.cnam.fr/index.php/publis/article/view?id=2744 http://cedric.cnam.fr/index.php/publis/article/view?id=2744 This paper proposes a resource allocation and decoding strategy at the secondary systems for underlay and interweave multi-carrier cooperative cognitive radio. The objective is to maximize the sum rate of both primary and secondary systems, taking into account the interference threshold constraint and the fact that the primary receiver always considers interference as noise. The decoding strategy at the secondary receivers is either Successive Interference Cancellation or treating interference as noise, depending on their channel gains. The sum rate and secondary rates are highly improved, compared with other resource allocation algorithms. The proposed algorithm benefits from multi-user diversity when the number of secondary cells increases. Tue, 14 May 2013 15:49:13 +0200 LAETITIA Paper http://cedric.cnam.fr/index.php/publis/article/view?id=2743 http://cedric.cnam.fr/index.php/publis/article/view?id=2743 This work proposes two new Resource Block (RB) allocation algorithms for the LTE uplink. They take into account the RB adjacency constraint and update the allocation metric. Two different heuristics are proposed: an Opportunistic and Efficient RB allocation Algorithm (OEA) and a Quality of Service based Opportunistic and Efficient RB allocation Algorithm (QoS based OEA). Both algorithms seek to maximize the aggregate throughput and avoid RB wastage unlike other algorithms in the literature. The complexity of the proposed algorithms are also computed analytically and compared to other well known heuristics. Tue, 14 May 2013 15:41:40 +0200 LAETITIA Paper http://cedric.cnam.fr/index.php/publis/article/view?id=2742 http://cedric.cnam.fr/index.php/publis/article/view?id=2742 Tue, 14 May 2013 14:12:05 +0200 MSDMA Paper http://cedric.cnam.fr/index.php/publis/article/view?id=2741 http://cedric.cnam.fr/index.php/publis/article/view?id=2741 Tue, 14 May 2013 12:02:05 +0200 MSDMA Paper http://cedric.cnam.fr/index.php/publis/article/view?id=2740 http://cedric.cnam.fr/index.php/publis/article/view?id=2740 Tue, 14 May 2013 11:50:19 +0200 MSDMA Paper http://cedric.cnam.fr/index.php/publis/article/view?id=2739 http://cedric.cnam.fr/index.php/publis/article/view?id=2739 Tue, 14 May 2013 11:43:53 +0200 MSDMA Paper http://cedric.cnam.fr/index.php/publis/article/view?id=2738 http://cedric.cnam.fr/index.php/publis/article/view?id=2738 We address the problem of clustering individuals described by several homogeneous blocks of variables. Reformulating it as problem of consensus of partitions, we propose a method based on the three way method STATIS to find a unique partition of the individuals. A real example on environmental data illustrates the proposed method Tue, 14 May 2013 11:31:22 +0200 MSDMA Paper http://cedric.cnam.fr/index.php/publis/article/view?id=2737 http://cedric.cnam.fr/index.php/publis/article/view?id=2737 Competing risks model time to first event and type of first event. An example from hospital epidemiology is the incidence of hospital-acquired infection, which has to account for hospital discharge of non-infected patients as a competing risk. An illness-death model would allow to further study hospital outcomes of infected patients. Such a model typically relies on a Markov assumption. However, it is conceivable that the future course of an infected patient does not only depend on the time since hospital admission and current infection status but also on the time since infection. We demonstrate how a modified competing risks model can be used for nonparametric estimation of transition probabilities when the Markov assumption is violated. Sat, 11 May 2013 15:15:56 +0200 MSDMA Paper http://cedric.cnam.fr/index.php/publis/article/view?id=2736 http://cedric.cnam.fr/index.php/publis/article/view?id=2736 In the last few years appeared pedagogical propositional natural deduction systems. In these systems, one must satisfy the pedagogical constraint: the user must give an example of any introduced notion. First we expose the reasons of such a constraint and properties of these "pedagogical" calculi: the absence of negation at logical side, and the "usefulness" feature of terms at computational side (through the Curry-Howard correspondence). Then we construct a simple pedagogical restriction of the calculus of constructions (CC) called CCr. We establish logical limitations of this system, and compare its computational expressiveness to Godel system T. Finally, guided by the logical limitations of CCr, we propose a formal and general de?nition of what a pedagogical calculus of constructions should be. Tue, 30 Apr 2013 00:58:59 +0200 CPR Paper http://cedric.cnam.fr/index.php/publis/article/view?id=2735 http://cedric.cnam.fr/index.php/publis/article/view?id=2735 Les systèmes pédagogiques sont apparus récemment à propos des calculs propositionnels (jusqu'à l'ordre supérieur), et consistent à donner systématiquement des exemples des notions (hypothèses) introduites. Formellement, cela revient à contraindre la règle d'hypothèse (Hyp) en déduction naturelle en une règle (P-Hyp) nécessitant la donnée d'exemples (i.e. instances prouvées) de formules introduites dans l'environnement. Autrement dit pour mettre un ensemble G de formules en hypothèse, il est requis de donner une substitution s telle que l'instance s(G) soit démontrable. Cette nécessité d'exemplification ayant été pointée du doigt par Poincaré (1913) comme relevant du bon sens: une définition d'un objet par postulat n'ayant d'intérêt que si un tel objet existe. Cette restriction appliquée à des systèmes formels intuitionnistes rejoint l'idée des mathématiques sans négation défendues par Griss (1946) au milieu du siècle dernier, et présentées comme une version radicale de l'intuitionnisme. À travers l'isomorphisme de Curry-Howard (1980), la contrepartie calculatoire est l'utilité des programmes définis dans les systèmes fonctionnels correspondant: toute fonction peut être appliquée à un argument clos. Les premiers résultats concernant les calculs propositionnels jusqu'au second ordre ont été publiés récemment par Colson et Michel (2007, 2008, 2009). Nous exposons dans ce rapport une tentative d'uniformisation et d'extension au Calcul des Constructions (CC) des précédents résultats. Tout d'abord une définition formelle et précise de sous-système pédagogique du Calcul des Constructions est introduite, puis différents tels sous-systèmes sont déclinés en exemple. Tue, 30 Apr 2013 00:47:42 +0200 CPR Paper http://cedric.cnam.fr/index.php/publis/article/view?id=2734 http://cedric.cnam.fr/index.php/publis/article/view?id=2734 Theorem proving is crucial for the formal validation of properties about user specifications. With the help of the Coq proof assistant, we show how to certify properties about conditional specifications that are proved using automated proof techniques like those employed by the Spike prover, a rewrite-based implicit induction proof system. The certification methodology is based on a new representation of the implicit induction proofs for which the underlying induction principle is an instance of Noetherian induction governed by an induction ordering over equalities. We propose improvements of the certification process and show that the certification time is reasonable even for industrial-size applications. As a case study, we automatically prove and certify more than 40% of the lemmas needed for the validation of a conformance algorithm for the ABR protocol. Tue, 30 Apr 2013 00:36:53 +0200 CPR Paper http://cedric.cnam.fr/index.php/publis/article/view?id=2733 http://cedric.cnam.fr/index.php/publis/article/view?id=2733 The report describes the main features of a cyber game environment for alternate reality environment/games. It helps to enrich research efforts. Behaviour change is a key issue addressed by the project. Fri, 19 Apr 2013 15:26:56 +0200 SEMpIA Paper http://cedric.cnam.fr/index.php/publis/article/view?id=2732 http://cedric.cnam.fr/index.php/publis/article/view?id=2732 Providing engaging interpretation resources for museum and gallery visitors may have a great impact on the overall museum visiting experience all by assisting museums in maintaining long-term relationships with their public. This paper focuses on the ways through which AR can be employed in museum and gallery settings as an interpretation medium. It also introduces a new generation of multimedia guides for the museum visit inspired by the concept of Adaptive Augmented Reality (A2R). Adaptive Augmented Reality (A2R) provides visual and acoustic augmentations that come to supplement the artefact or site viewed by a museum or gallery visitor and monitors the cognitive and affective impact of all interactions of the museum visitor both with the physical and the digital environment. The ultimate goal is to make every museum visit unique, by tailoring an Augmented Reality visit with contents that are susceptible to increase the affective impact of the augmented museum visiting experience and hence encourage intrinsic and self-motivated learning. Fri, 19 Apr 2013 13:34:46 +0200 ILJ Paper http://cedric.cnam.fr/index.php/publis/article/view?id=2731 http://cedric.cnam.fr/index.php/publis/article/view?id=2731 A large section of the cultural heritage sector not usually thought of as Cultural Heritage is the contemporary and temporary art galleries and spaces. Many such institutions do not have traditional collection mechanisms nor permanent artefacts and exhibitions, but rather a rolling programme constantly in flux. This represents a new challenge in terms of a systemised approach to learning and public engagement strategies, but also offers an opportunity to propose new learning and engagement mechanisms through the prism of its one unique selling point? the artistic creative engagement of artists and art practitioners. This paper examines the potential of Augmented Reality for the museum and gallery visiting experience focusing particularly on the ways through which AR as an emerging technology may inform emerging art practices all by encouraging public participation and engagement with art. Fri, 19 Apr 2013 13:21:12 +0200 ILJ Paper http://cedric.cnam.fr/index.php/publis/article/view?id=2730 http://cedric.cnam.fr/index.php/publis/article/view?id=2730 À travers la description des principes et de la mise en ?uvre de la seconde étape du jeu pervasif PLUG, les responsables du projet analysent les perspectives de son utilisation comme outil pédagogique permettant d?aller plus loin dans l?expérience de visite ainsi que les possibilités offertes à l?institution muséale dans sa réflexion sur les nouvelles formes de la médiation. Fri, 19 Apr 2013 13:14:34 +0200 ILJ Paper http://cedric.cnam.fr/index.php/publis/article/view?id=2729 http://cedric.cnam.fr/index.php/publis/article/view?id=2729 We present a laser ranging system, under development, that uses a high frequency modulated beam to achieve sub-nm resolution by the combined use of interferometric and time-of-flight measurements. We first describe how the absolute distance is extracted from a two-mode interference signal. In particular we show that the signal, which presents both optical and synthetic wavelength scales, is essential to achieve nm-scale accuracy, despite the significant long-term phase drifts in the 20 GHz detection chains. Then we present results obtained with the telemeter implemented on an optical table, for a distance of about four meters, implemented by folding the laser beam path to the target. The challenge here is to achieve a phase and amplitude measurement of two 20 GHz signals with a resolution well below 10-4 cycle and 10-4, respectively, despite the fact that the signal undergoes very strong (×3 ) amplitude changes. Thu, 18 Apr 2013 14:48:39 +0200 LAETITIA Paper http://cedric.cnam.fr/index.php/publis/article/view?id=2728 http://cedric.cnam.fr/index.php/publis/article/view?id=2728 . Thu, 18 Apr 2013 10:32:12 +0200 LAETITIA Paper http://cedric.cnam.fr/index.php/publis/article/view?id=2727 http://cedric.cnam.fr/index.php/publis/article/view?id=2727 This paper deals with interval state observer design for time-varying discrete-time systems. The problem of a similarity transformation computation which connects a (time-varying) matrix and its nonnegative representation is studied. Three solutions are proposed: for a generic time-varying system, a system with positive state, and for a particular class of periodical systems. Numerical simulations are provided to demonstrate advantages of the developed techniques. Wed, 10 Apr 2013 11:05:50 +0200 LAETITIA Paper http://cedric.cnam.fr/index.php/publis/article/view?id=2726 http://cedric.cnam.fr/index.php/publis/article/view?id=2726 Proceedings of the conference Sun, 24 Mar 2013 21:14:47 +0100 ISID Paper http://cedric.cnam.fr/index.php/publis/article/view?id=2725 http://cedric.cnam.fr/index.php/publis/article/view?id=2725 Proceeedings of the conference Sun, 24 Mar 2013 20:59:06 +0100 ISID Paper http://cedric.cnam.fr/index.php/publis/article/view?id=2724 http://cedric.cnam.fr/index.php/publis/article/view?id=2724 The LTE specification providesQoS for multimedia services with fast connectivity, high mobility and security. However, 3GPP specifications have not defined scheduling algorithms to exploit the LTE characteristics to support real time services. In this article we propose a two level scheduling scheme composed by cooperative game theory, a virtual token mechanism, and the well known algorithms EXP-RULE and M-LWDF in downlink system. By using cooperative game theory such as bankruptcy game and Shapley value, the proposed mechanism works by forming coalitions between flow classes to distribute the bandwidth fairly among all them. Both algorithms EXP-RULE andM-LWDF have been modified to use a virtual token mechanism to improve their performance, giving priority to real time flows. By taking the arrival rates of packets into account, the proposed mechanism partially included in previous schedulers has been adapted to this work to increase remarkably the performance of the resource allocation for real time flows. The performance evaluation is conducted in terms of system throughput, packet loss ratio (PLR), total cell spectral efficiency, delay and fairness index. Tue, 19 Mar 2013 15:39:38 +0100 SEMpIA Paper http://cedric.cnam.fr/index.php/publis/article/view?id=2723 http://cedric.cnam.fr/index.php/publis/article/view?id=2723 We introduce the Digital Roll, a cylindrical hand-held device wrapped with a curved display, that can be rotated by hand to provide a continuous scrolling of text. We present design considerations for such a device and report on a preliminary experiment designed to assess its acceptance for casual reading, using a simulator. Encouraging results and their implications on the design of the device are then discussed. Tue, 19 Mar 2013 14:18:59 +0100 ILJ Paper http://cedric.cnam.fr/index.php/publis/article/view?id=2722 http://cedric.cnam.fr/index.php/publis/article/view?id=2722 Bilogic PERT networks can be used to model the execution of parallel and/or sequential programs. If the various tasks composing the program are given random durations, the problem of computing the program completion time is NP-hard. We describe a low polynomial complexity algorithm that provides bounds and approximations of the completion time using properties of integral orderings among random variables. The algorithm is tested on some examples of large graphs and proves to be satisfactory. Mon, 18 Mar 2013 11:10:38 +0100 ILJ Paper http://cedric.cnam.fr/index.php/publis/article/view?id=2721 http://cedric.cnam.fr/index.php/publis/article/view?id=2721 This paper addresses the issue of improving quality of business process (BP) models by exploiting domain knowledge. Indeed, business process models reflect the business processes of companies. The success of these processes has a direct and undeniable impact on business operations success. Managing them through their underlying models helps improving their effectiveness, consistency, and transparency. BP modeling aims at a better understanding of processes, allowing deciders to achieve strategic goals of the company. However, several studies from literature showed that inexperienced system analysts often produce low level quality. This situation is partly due to lack of domain knowledge. In this paper we propose to support this modeling effort with an approach that uses domain knowledge to improve the semantic quality of BP models. We suggest to use ontologies as a mean to capture domain knowledge and meta-modeling techniques to deal with BP models independently of languages in which they are expressed. Our contribution is threefold: 1) the meta-models describing both a domain ontology and a BP model are described, 2) the alignment between the concepts of both meta-models is dened and illustrated, 3) a set of OCL (Object Constraint Language) mapping rules is provided. A simple case study illustrates the process. Thu, 14 Mar 2013 13:45:54 +0100 ISID Paper http://cedric.cnam.fr/index.php/publis/article/view?id=2720 http://cedric.cnam.fr/index.php/publis/article/view?id=2720 Cet ouvrage est consacré à un domaine de recherche porteur de nombreux développements, tout particulièrement depuis une quinzaine d'années. L'une des innovations des modèles à variables latentes est de prendre en compte des variables inobservables, causes de phénomènes qui, eux, peuvent s'observer directement. Cette formalisation permet de fédérer de nombreuses méthodes utilisées dans des domaines très divers de la statistique : ? l'analyse factorielle, ? l'analyse en classes latentes, ? les modèles structurels où des blocs de variables sont expliqués chacun par des variables latentes, elles-mêmes reliées entre elles par un graphe de causalité, ? les modèles de mélange fini de distributions. Cet ouvrage est le fruit de la collaboration entre spécialistes parmi les plus réputés Mon, 11 Mar 2013 23:26:25 +0100 MSDMA Paper http://cedric.cnam.fr/index.php/publis/article/view?id=2719 http://cedric.cnam.fr/index.php/publis/article/view?id=2719 High dimensional data means that the number of variables p if far larger than the number of observations n. This occurs in several fields such as genomic data or chemometrics. This didactic talk starts from a survey of various solutions in linear regression and present afterwards their extensions to unsupervised « sparse » methods for principal components analysis (PCA) and multiple correspondence analysis (MCA). When p>n the OLS estimator does not exist for linear regression. Since it is a case of forced multicollinearity, one may use regularized techniques such as ridge regression, principal component regression or PLS regression: these methods provide rather robust estimates through a dimension reduction approach or with explicit (or not) constraints on the regression coefficients. The fact that all the predictors are kept is often considered as a positive point. However if p>>n it becomes a drawback since a combination of all variables cannot be interpreted. Sparse combinations, ie with a large number of zero coefficients are preferred. Lasso, elastic net, sparse PLS perform simultaneously regularization and variable selection thanks to non quadratic penalties: L1, SCAD etc. We will present variants such as the group-lasso when the variables are structured in blocks. In PCA, the singular value decomposition shows that if we regress principal components onto the input variables, the vector of regression coefficients is equal to the factor loadings. It suffices to adapt sparse regression techniques to get sparse versions of PCA and of PCA with groups of variables. We conclude by a presentation of a sparse version of Multiple Correspondence Analysis. Sun, 10 Mar 2013 18:55:48 +0100 MSDMA Paper http://cedric.cnam.fr/index.php/publis/article/view?id=2718 http://cedric.cnam.fr/index.php/publis/article/view?id=2718 YAO poster presentation. Sun, 03 Mar 2013 12:23:39 +0100 MSDMA Paper